1. Field of the Invention
The present invention relates to an electron emission lithography apparatus and method using a selectively grown carbon nanotube. More particularly, the present invention relates to an electron emission lithography apparatus and method in which a selectively grown carbon nanotube is used as an electron emission source in order to perform nano-patterning and a track of an electron is precisely controlled using a magnetic field.
2. Description of the Related Art
Lithography is a technique of transferring a pattern of a mask onto a thin resist formed on a surface of a substrate, such as a semiconductor wafer. Generally, lithography can be divided into two types, optical lithography and radiation lithography. Optical lithography indicates ultraviolet (UV) lithography and radiation lithography indicates lithography using an X-ray, electron beam (e-beam), or ion beam.
Using conventional optical lithography, it is difficult to achieve a precise critical dimension of 70 nm or less. In the case of electron beam lithography, a deviation occurs between the center of a substrate and the edge thereof due to the characteristics of the electron beam. Thus, it is necessary to perform electron beam lithography on a single substrate many times in order to reduce the deviation. Resultantly, a throughput of a lithography apparatus is reduced significantly.
In an effort to solve the above-described problems, it is a feature of an embodiment of the present invention to provide an electron emission lithography apparatus and method using a selectively grown carbon nanotube as an electron emission source for lithography to control a critical dimension precisely, to prevent occurrence of a deviation throughout a sample, which is an object of lithography, and to increase throughput.
To provide this feature of the present invention, an embodiment of the present invention provides an electron emission lithography apparatus including an electron emission source installed within a chamber and a stage, which is separated from the electron emission source by a predetermined distance and on which a sample is mounted, wherein the electron emission source is a carbon nanotube having electron emission power.
Preferably, the electron emission source is manufactured by forming a carbon nanotube in a porous substrate, and preferably, the porous substrate includes Si or Al2O3.
Also preferably, the electron emission lithography apparatus further includes a magnetic field generator that can apply a magnetic field to electrons emitted from the carbon nanotubes and an insulator thin film patterned on the carbon nanotube.
Another feature of an embodiment of the present invention provides an electron emission lithography method using a carbon nanotube. The electron lithography method includes (a) applying voltage to a substrate having a carbon nanotube to emit electrons from the carbon nanotube; (b) controlling the emitted electrons to reach a position corresponding to the carbon nanotube on a sample; and (c) performing lithography on an electron beam resist formed on the sample by the electrons.
In an embodiment of the present invention, (b) may be performed by applying a magnetic field to the emitted electrons using a magnetic field generator. Alternatively, (b) may be performed by controlling the intensity of the magnetic field applied to the electrons according to the distance between the carbon nanotube and the electron beam resist on the sample.
Another feature of an embodiment of the present invention provides a method of manufacturing an electron emitter for lithography. The method includes (a) forming nano templates for forming carbon nanotubes by performing anodizing on a substrate; (b) growing carbon nanotubes in the nano templates by injecting a carbon nanotube growing gas; and (c) forming a nonconductive layer on predetermined portions of the carbon nanotubes.
Preferably, (a) includes forming holes at positions where the carbon nanotubes are to be grown by performing a first anodizing process; and forming the nano templates for growing the carbon nanotubes at the positions of the holes by performing a second anodizing process.
Preferably, in (b) the growing gas is methane and (b) additionally includes injecting a diluent gas, such as argon or nitrogen.
Yet another feature of an embodiment of the present invention provides a method of manufacturing an electron emitter for lithography. The method includes (a) selectively forming nano templates for forming carbon nanotubes in a substrate by performing anodizing on the substrate; and (b) growing carbon nanotubes in the nano templates formed at selected positions by injecting a carbon nanotube growing gas into the substrate.